NuTone door chime problems

I have an old (like most stuff in the house I live in) NuTone musical door chime. It is electronic and you can select several different songs. It has a speaker like you would find in a radio or stereo. It is a two button (two door) chime. It is fed from a Rittenhouse RT34 transformer attached to the electric panel in the basement.

The chime started making a very loud humming/buzzing sound, coming from the speaker of the chime.

The noise occurs when both door buttons are disconnected. The noise stops when I cut power to the circuit with the circuit breaker, and when I disconnect the DC wire in the chime itself.

The question is, how do I determine if the transformer is bad, or the electronic chime is bad? Thanks.

I have an old (like most stuff in the house I live in) NuTone musical door chime. It is electronic and you can select several different songs. It has a speaker like you would find in a radio or stereo. It is a two button (two door) chime. It is fed from a Rittenhouse RT34 transformer attached to the electric panel in the basement.

The chime started making a very loud humming/buzzing sound, coming from the speaker of the chime.

The noise occurs when both door buttons are disconnected. The noise stops when I cut power to the circuit with the circuit breaker, and when I disconnect the DC wire in the chime itself.

The question is, how do I determine if the transformer is bad, or the electronic chime is bad? Thanks.

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It sounds like maybe a open Capacitor or a shorted audio driver or rectifier.

The transformers usually open, and just go dead. Sounds like it is making power.

The power to the doorbell switches and the chime itself is 24vac coming from the transformer, not a DC voltage. With an electronic chime, internally it will take that ac and make dc to run the circuits. Sounds like the amplifier in the chime is going bad. Probably easiest to just replace the thing.

Note, I had an electronic one for awhile, but its internal circuity would pick up my neighbor's ham radio transmissions just like I was sitting in the room with him...very annoying. I swapped it out for a simple ding/dong non-electronic one.